[en] Aim of the inquiry: Clarification of the mechanism of HTS superconducting transition broadening induced by magnetic field with a study of magnetically and thermally modulated microwave absorption in Y- Ba - Cu - O- single crystals near their critical temperatures and an experimental examination of the Fistul theory and models describing influence of Abrikosov vortices on critical current of the Josephson Junction and a nature of microwave responses in HTS - ceramics, correspondingly, was the aim of the inquiry. Method of the inquiry: For the first time temperature modulation method has been developed and used for microwave investigations along with conventional magnetic field modulation one. The results achieved and their novelty: Temperature dependencies of the temperature derivative of absorption (∂R / ∂T) and magnetic field one (∂R / ∂H) were observed to have superconducting transition peaks differently shaped and shifted one with respect to another. It was found out that the peaks responded differently when external magnetic field and angle between single crystal c axis and magnetic field direction were changing. It was shown that the behaviors of weak field peaks and their angle dependences could be well described by the Tinkham model only if it was certainly modified. It was shown that the 'low-field signal' could de used for studying the vortices structure of the remanent field in 1 - 2 - 3 - ceramics. Fistul formula describing critical current of intergrain Josephson junctions in dependence on concentrations of Abrikosov vortices on their sides was directly confirmed by the experimental data. (author)

[en] The diagnostics system of the charged particle beam of the JINR synchrophasotron realised on the base of proportional analog chamber with the current data output is described. For data acquisition, processing and visualization the DVK1 computer interfaced with the CAMAC crate and supplied by external devices (floppy discs, printer and colour display) are used. The results of experimental investigation of the temperature instability of input amplifiers, the choice of elements of protection a gainst overvoltage and problems of organizing the system operation are discussed in detail

[en] The microwave absorption R in the Y₁Ba₂Cu₃O_7-x single crystals was investigated near Tc ∼ 92K and in the external magnetic field 0 < H le 9kOe kOe. A modified ESR spectrometer was used in the experiment. The method of temperature modulation, along with the usual method of magnetic-field modulation, was first applied in studying of the microwave response of these crystals. Peaks in the temperature dependencies of the signals ∂R/∂H and ∂R/∂T observed in the vicinity of Tc were differently shaped and shifted one with respect to another. The evolution of the peaks with variation of the magnetic field and angle θ between H and the c-axis was traced. It has been shown that the observed difference of the temperature dependencies of the derivatives ∂R/∂H and ∂ R/∂T occurs due to the field-induced broadening of the superconducting transition, which is inherent in the high-Tc superconductors

[en] The HTSC monocrystals Ho₁Ba₂Cu₃O_7-δ with T_c = 86.8 K was studied at the modified EPR-spectrometer at the T > 78 K. The signal was observed, the spectrum whereof in the area of fields H < 0.7 Oe had the form of equilibrium absorption lines with the ΔH = 9 x 10^-3 Oe interval. The dependence of the spectrum on the Shf-field amplitude, on the monocrystal temperature and orientation was measured in detail

[en] Fluxes of scattered bremsstrahlung γ-radiation of E₀ = 22 MeV energy electrons to the front and to the back hemisphere from plane lead, iron, aluminium, glass textolite scattering targets characterized by various thickness were studied. The study of radiation scattered to the front hemisphere was shown to enable to obtain information on the physical features of d > 25 g · cm^-2 thickness probed objects

No abstract available

[en] Fission process of nuclear materials is accompanied by the yield of fission fragments and corresponding emission of γ-quanta and fission neutrons. In this work comparative analysis of effectiveness of registration of radioactive elements by two various methods: double γ-quanta coincidence and neutron detection methods. In the frame of developed approach the analysis of comparative effectiveness of registration methods for some fissile materials was done

[en] The effect of low-temperature annealing on the magnetization curve of YBa₂Cu₃O_6+x ceramics in the superconducting state (x ∼ 0.9) is investigated. When the annealing time is fairly long, the field dependence of magnetic moment M exhibits a feature in the form of a plateau, where the value of M remains almost constant. The evolution of this feature in the magnetization curves of annealed samples with annealing time and temperature is studied. It is assumed that low-temperature annealing gives rise to metastable ferromagnetic clusters in YBa₂Cu₃O_6+x ceramics, the contribution of which to the magnetic moment accounts for the feature in the magnetization curves of the annealed samples

No abstract available

[en] It is described the developed and created complex of installations of X-ray emission analysis with direct and two-stage excitation of X-ray radiation elements of the sample by radionuclide gamma and alpha - particle radiation. The created co mplex of installations allows to determine the contents of elements in samples up to 10^-5 g/g with precision not worse than 20 in plant, soil, and other samples. (author)